Circuit interrupter



July 20, 1948. w, M, LEEDSA 2,445,529

CIRCUIT INTERRUPTER Filed Sept. 19, 1944 Eg. z

Z. w? I BY I'iATORNEY Patented July 20, 1948 CIRCUIT INTERRUPTER Winthrop M. Leeds, Pittsburgh, Pa., assigner to Westinghouse ElectricCorporation, East Pittsburgh, lla., a corporation of Pennsylvania Application September 19, 1944, Serial No. 554,788

Claims. (Cl. Zilli-148) This invention relates to circuit interrupters in general, and more particularly to arc extinguishing structures therefor. In apatent application rlled August 12, 1942, Serial No. 454,515, by Winthrop M. Leeds and assigned to the assignee of the instant application, now U. S. Patent 2,359,127 issued September 26, 1944, there is disclosed and claimed a novel circuit interrupting structure in which a plurality of staggered movable bridging contacts simultaneously separate to establish a plurality of serially related arcs, which practically simultaneously merge into a single arc of considerable length. Deionizing activity is brought into play to effect the extinction of the single merged arc. The aforesaid patent not only describes the structure involved but presents a working theory to explain the considerable success obtained during tests made on such a device. The contact structure is operable to Very rapidly draw a single arc o considerable length in a much faster time than is possible using conventional contact structures. It is an object of the present invention to provide an improved operating arrangement for effecting the simultaneous separation of the staggered movable bridging contacts to simplify the arrangement utilized in the aforesaid patent.

In the present application I propose to use a fluid blast, which may be either a gaseous blast or a liquid blast, to not only eiect the lateral separation of the plurality of bridging contacts but also to utilize said fluid blast in electing the extinction of the single merged arc.

Another object is to provide an improved circuit interrupter of the aforesaid type in which means are provided to form a plurality of orices through which the single merged are is drawn.

Further objects and advantages will readily become apparent upon a reading of the following specification taken in conjunction with the drawing in which:

Figure 1 is a vertical sectional view through one embodiment of my invention, the parts being shown in the closed circuit position.

Fig. 2 is a View similar to Fig. 1 but showing the disposition of the parts at an intermediate point in the opening operation and utilizing a different means for providing the fluid blast.

Fig. 3 is a sectional view taken along the line III--III of Fig. 2, and

Fig. 4 is a perspective view of one of the plates used within the casing,

Referring to the drawing, and more particularly to Fig. 1 thereof, the reference numeral I designates a casing which is preferably composed of insulating material and having a cover portion 2 integrally formed therewith. The cover 2 resiliently supports a stationary contact 3, the latter being resiliently supported by a spring 4 within a housing 5 having vents 6 to minimize back-pressure when the Contact 3 is raised.

The stationary contact 3 makes abutting engagement with a plurality of staggered movable bridging contacts 'I abutting each other in sideby-side manner in the closed circuit position as shown in Fig. 1. There are two sets of such bridging contact blocks generally designated by the reference numerals 49 p and 4l. Compression springs 3 bias the contacts 'I into engagement within piston chambers 42. Co-operable with the lowermost Contact 'I is a tubular movable contact 9 having secured thereto at its lower end a piston i8 operable Within a piston chamber Il. Sliding contacts I?! are preferably provided to make electrical contact between the movable contact 9 and the piston chamber i I to which the line terminal I3 may be secured. The other line terminal I4 may be secured to the upper end of the stationary contact 3. A conduit I5 is provided to admit opening air to the top side of the piston I0, and a second conduit I5 is employed to admit closing air or gas to the lower side of the piston I0.

Disposed within the lower end of the casing I is an insulating plug member Il having an annular recess I8 and also having an aperture I9 through which the movable contact 9 is guided. Positioned within the interior of the casing I are a plurality of, in this instance three, annular baille plates 36a which form a plurality of orifices 2l as more clearly shown in Fig. 3. Fig. 4 shows more clearly the configuration of the insulating plate members 36a. It will be observed that the upper orice 2l is closed by the contact 3, being biased to its lower position by the spring 4.

The operation of the interrupter shown in Fig. 1 will now be explained. In the closed circuit position the electrical circuit therethrough comprises the line terminal I4, stationary contact 3, contacts '1, movable contact 9, sliding contacts I2, piston chamber I I, to line terminal I3. To effect an opening operation a iluid blast is introduced through the conduit I5. The fluid blast through the conduit I5 acts on the upper side of the piston Iii and through the vents 22 to the region 23 within the tubular contact 8. The fluid blast then enters the region 2!! between the contacts 'I and forces the contacts I laterally apart against the biasing action of the springs 8 Within the piston chambers I2. Preferably vents 25 are provided to minimize back pressure behind the contacts-1.

The lateral separation of the contacts 'l initially establishes a, plurality of serially related arcs therebetween as designated by the dotted lines 26 in Fig. 2. However, the region 24 practically simultaneously becomes ionized to the eXtent that it permits a single merged arc designated by the line 21 to be established between the stationary Contact 3 and the movable contact 9 as more clearly shown in Fig. 2. The single merged arc 21 is subjected to a fluid blast passing longitudinally thereof, through the orifices 2|, raising the contact 3 and passing out of the casing I through vents 28 provided through the cover portion 2. The result is an immediate extinction of the single merged arc Z1,

Following interruption of the circuit and when the movable contact 9 is in its lowermost position, that is, with piston Ill abutting the bottom of piston chamber Il, the fluid blast may be stopped, and the separation between the lowermost contact 1 and the movable contact 9 depended upon the provide the isolating gap in the circuit following reclosure of the contacts 1.

To reclose the interrupter, a fluid blast is passed through the conduit I6 to drive the piston l0 upwardly to thereby effect a re-engagement between the movable contact 9 and the lowermost contact 1.

In the arrangement shown in Fig. 2, there is a slightly different means provided to furnish the uid blast through the movable contact 9. A piston 29 is secured to and movable with the movable contact 9 and operable within a piston chamber 30 having a vent 3| controlled by a check valve 32 disposed at its lower end. Consequently, upon downward movement of the movable contact 9 as caused by operating means moving the extension 33 thereof, the piston 29 will move downwardly within the piston chamber 30 closing the check valve 32 and forcing fluid from the region 34 through apertures 35 and into the region 23 within the movable contact 9. The interruption process is the same as previously described.

During the closing operation of the interrupter shown in Fig. 2, the extension 33 is raised by suitable actuating means not shown to cause a raising of the piston 29 within the piston chamber 30 to thereby cause an opening of the check valve 32 and a consequent drawing of iiuid into the region 34 through the vent 3|. The interrupter is then in readiness for the next opening operation.

From the foregoing description it will be apparent that my invention simplifies the opening of the contacts 1 and provides a means to quickly effect the extinction of the single merged arc '21. Also the utilization of a fluid blast may be used to flush out the casing I following a circuit interrupting opening operation. The resulting mechanical simplification makes possible the application of this interrupter to porcelainclad oil-poor breakers or to high-voltage compressed-air circuit breakers.

It will be observed that the upper stationary .contact 3 serves as a pressure controlled venting valve for the upper orice 2|. It is also to be noted that the interrupter shown in Fig. 2 shows how fluid pressure may be provided by a piston operated from a suitable conventional mechanism.

Although I have shown and described specific structures, it is to be clearly understood that the Vsame w-ere merely for purpose of illustration and Vthat changes and modifications may readily be made by those skilled in the art without departing from the spirit and scope of the appended claims.

I claim as my invention:

1. A circuit interrupter of the fluid blast type including a relatively stationary contact, a movable contact, means for moving the movable contact to the open circuit position and for spacing the movable contact from the relatively stationary contact in the closed circuit position of the interrupter, two sets of movable bridging contact blocks, the one or more contact blocks of each set all being movable and staggered in side-byside abutting engagement with the one or more movable contact blocks of the other set, the two sets being arranged to move in substantially opposite directions and in the closed circuit position of the interrupter bridging conductively the space between the relatively stationary contact and the movable contact, a piston chamber for each movable bridging contact block, means biasing each movable bridging contact block within its respective piston chamber toward the closed circuit position, and means permitting the entrance of a blast of fluid into the arcing region to raise the fluid pressure therein to a sufficient extent to cause the simultan-cous lateral separating motion of all the movable bridging contact blocks within their respective piston chambers against the action of the biasing means, the initial separating motion of the contact blocks causing the establishment of a plurality of serially related arcs in zig-zag manner within the arcing region, further separating motion of the Contact blocks causing a coalescence of the several arcs into a single arc of considerable length extending between the relatively stationary and movable contacts, and the blast of fluid causing the extinction of the single merged arc.

2. A circuit interrupter of the fluid blast type including means defining an elongated substantially enclosed arc passage, a relatively stationary contact positioned at one end of the substantially enclosed arc passage, a movable contact spaced away from the relatively stationary contact within the substantially enclosed arc passage in the closed circuit position of the interrupter, two sets of movable bridging contact blocks, the one or more contact blocks of each set all being movable and staggered in side-byside abutting engagement with the one or more movable contact blocks of the other set, the two sets being arranged to move in substantially opposite directions and in the closed circuit position of the interrupter bridging conductively the space between the relatively stationary contact and the movable contact, a piston chamber for each movable bridging contact block, means biasing each movable bridging contact block within its respective piston chamber toward the closed circuit position, and means permitting the entrance of a blast of fluid into the arc passage to raise the uid pressure therein to a sufficient extent to cause the simultaneous lateral separating motion of all the movable bridging contact blocks within their respective piston chambers against the action of the biasing means, the initial separating motion of the contact blocks causing the establishment of a plurality of serially related arcs in zig-zag manner within the arc passage, further separating motion of the contact blocks causing a coalescence of the several Iarcs into a single arc of considerable length extending between the relatively stationary and movable contacts, and the blast of lluid causing the extinction of the single merged arc.

3. A circuit interrupter of the uid blast type including a relatively stationary contact, a movable contact, means for moving the movable contact to the open circuit position and for spacing the movable contact from the relatively stationary contact in the closed circuit position of the interrupter, two sets of movable bridging contact blocks, the one or more contact blocks of each set al1 being movable and staggered in side-by-V side abutting engagement with the one or more movable contact blocks of the other set, the two sets being arranged to move in substantially opposite directions and in the closed circuit position f the interrupter bridging conductively the space between the relatively stationary contact and the movable contact, a piston chamber for each movable bridging contact block, means biasing each movable bridging contact block within its respective piston chamber toward the closed circuit position, and means permitting the entr-ance of a blast of iiuid into the arcing region to raise the fluid pressure therein to a suiiicient extent to cause the simultaneous lateral separating motion of al1 the movable bridging contact blocks within their respective piston chambers against the action of the biasing means, the initial separating motion of the contact blocks causing the establishment of a plurality of serially related arcs in zig-zag manner within the arcing region, further separating motion of the contact blocks causing a coalescence of the several arcs into a single arc of considerable length extending between the relatively stationary and movable contacts, the blast of fluid causing the extinction of the single merged arc, and means defining a plurality of orifices lspaced lalong the arcing region through which the single arc extends.

4. A circuit interrupter of the fluid blast type including means defining an elongated substantially enclosed arc passage, a relatively stationary contact positioned at one end of the substantially enclosed arc passage, a movable contact spaced away from the relatively stationary contact within the substantially enclosed arc passage in the close circuit position of the interrupter, two sets of movable bridging contact blocks, the one or more contact blocks of each set all being movable and staggered in side-byside abutting engagement with the one or more movable contact blocks of the other set, the two sets being arranged to move in substantially opposite directions and in the closed circuit position of the interrupter bridging conductively the space between the relatively stationary contact and the movable contact, a piston chamber for each movable bridging contact block, means biasing each movable bridging contact block within its respective piston chamber toward the closed circuit position, and means permitting the entrance of a blast of fluid into the arc passage to raise the fluid pressure therein to `a sufficient extent to cause the simultaneous lateral separating motion of all the movable bridging contact blocks within their respective piston chambers against the action of the biasing means, the initial separating motion of the contact blocks causing the establishment of a plurality of serially related arcs in zig-zag manner within the arc passage, further separating motion of the contact blocks causing a coalescence of the several arcs into a single arc of considerable length extending between the relatively stationary and movable contacts, the blast of fluid causing the extinction of the single merged arc, and means defining a plurality of orices spaced along the arc passage through which the single arc `extends.

5. A circuit interrupter of the fluid blast type including means dening 'an elongated substantially enclosed arc passage, a relatively stationary contact positioned at one end of the substantially enclosed arc passage, a movable contact spaced laway from the relatively stationary contact within the substantially enclosed arc passage in the closed circuit position of the interrupter, two sets of movable bridging contact blocks, the one or more contact blocks of each set all being movable and staggered in side-byside abutting engagement with the one or more movable contact blocks of the other set, the two sets being |arranged to move in substantially opposite directions and in the closed circuit position of the interrupter bridging conductively the space between the relatively stationary contact and the movable contact, a piston chamber for each movable bridging contact block, means biasing each movable bridging contact block within its respective piston chamber toward the closed circuit position, and means permitting the entrance of a blast of fluid into the arc passage to raise the uid pressure therein to a sufficient extent to cause the simultaneous lateral separating motion of all the movable bridging contact blocks within their respective piston chambers against the action of the biasing means, the initial separating motion of the contact blocks causing the establishment of Ia plurality of serially related arcs in zig-zag manner within the arc passage, further separating motion of the contact blocks causing a coalescence of the several arcs into a single arc of considerable length extending between the relatively stationary and movable contacts, the blast of fluid causing the extinction of the single merged arc, and valve means for the said one end of the arc passage including the relatively stationary contact to permit the venting of fluid out of the arc passage upon a predetermined fluid pressure therein.

WINTHROP M. LEEDS.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 500,629 Thomson July 4, 1893 1,081,119 Johnson Dec. 9, 1913 1,334,645 Bechoi et al. Mar 23, 1920 2,133,938 Ruppel Oct. 18, 1938 2,249,499 Seaman July 15, 1941 2,255,198 Thommen Sept. 9, 1941 2,266,982 Milliken Dec. 23, 1941 2,365,131 Amer et al Dec. I2, 1944 2,419,446 Flurscheim Apr. 22, 1947 FOREIGN PATENTS Number Country Date 356,005 Great Britain Sept. 3, 1931 

